While not a K-3II, my K-3 is close enough that I feel it appropriate to put my 2-cents worth in...
I have been shooting with my early production K-3 since March of 2014. During that time,
I don't recall ever having a freeze. My general work involves:
- Fairly heavy use of live view for manual focus using vintage lenses
- Frequent, though not exclusive, use of both motor-in-lens and pawl-drive AF
- Occasional use of continuous shooting -- high
- Occasional interval and multiple exposure composites
- Very rare video
- Almost never interval movies
- Occasional long exposures for night/astro work, with duration extending to several minutes with sessions lasting several hours
- Product and table-top work using built-in, on-camera, and multiple flash setups
- A mix of Pentax, Wasabi, and DSTE batteries (six total) used in rotation
- Have never had a battery test at less than its nominal voltage unless discharged into the red
- Never fast-charged. Always charged using the Pentax slow charger that came with the camera.
- Very seldom allowed to discharge into the "red" before swapping out for a fresh battery
- Only twice in five years has the camera shut down due to low battery
- Only once had a shutdown due to high camera temperature
- Do a fair amount of landscape work in all weather in a damp climate
I take part in a fair amount of help request the threads an my take on camera freeze with the K-3 goes like this:
- Not common and definitely not a general characteristic of the K-3 model
- Often involves power problems due to low voltage from batteries gone bad
- There is a correlation between use of the battery grip and camera freeze
- If not bad battery, water intrusion with internal corrosion is often to blame as might physical damage due to being dropped or similar
- Bad board in the electronics
If power problems are suspected, the last image made before a freeze may contain clues in the makernotes section of the file's EXIF metadata. Items of interest would include any tags for internal camera voltage and/or temperatures.
Steve